Rotary fluid-meter



(No Model.) 3 Sheets-Sheet l.

J. A. TILDEN.

ROMRY FLUID METER.

No. 385,970. Patented July 10, 1888.

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Patente J. A. TILDEN. ROTARY FLUID METER (No Model.)

SRR RV UNITED STATES PATENT OFFICE.

JAMES A. TILDEN, OF HYDE PARK, MASSACHUSETTS, ASSIGNOR TO THE HERSEYMETER COMPANY, OF PORTLAND, MAINE..

ROTARY FLUID-METER.

SPECIFICATION forming part cf Letters Patent No. saaevodatea July 1o,lees.

Application filed January 25, 1887. Serial No. 225,480. (No model.)`

To all whom it may concern:

Be it known that I, JAMEs A. TILDEN, of Hyde Park, inthe county ofNorfolk and State of Massachusetts, a citizen of the United States, haveinvented a new and useful Improvement in Fluid-Meters, of whichA thefollowing is a full, clear, and exact description, reference being hadto the accompanying drawings, forming a part of this specification, inexplaining its nature.

This invention relates to an improvement in fluid-meters. In myimprovement I employ a piston adapted to have an 'eccentric or siderocking motion across the cylinder-chamber to effect its division'at twoor more parts into receiving and discharging spaces. In order todiametrically divide the cylinder-chamber into receiving and dischargingspaces,and to maintain a'constant division during the continual changingof the piston, the relative shape of the piston and cylinder is suchthat a constantly-changing point of contact is secured as a bearing uponwhich the piston rocks. In all forms of meters of` this class so farconstructed the relative shape of the piston and cylinderchamber hasbeen suchthat the several contact bearings in performing their functionbrought at each rocking-point such a division of the cylinder as tocause the piston .to be' rigidly confined in its movement upon thesepoints. It will be readily understood that in this construction thelodgment of the slightest particle of material-such as sand, pipe-scale,or other substance contained in water-will thoroughly wedge and lock thepiston, and under heavy pressures of water breakage of the piston willoccur. It is to overcome the defect existing in this class of metersthat my invent'ion is intended, and to accomplish this result I adaptthe piston to the cylinder in such a manner that it is free or confinedupon its contact-points by hydraulic action 'instead of class of metersin which a piston rocks upon continually-changing points or lines ofcontact withthe cylinder-chamber, and in which the alternatingprojections and recesses upon the piston are less in number than in thecylinder, that constitutes my invention.

Referring to the drawings, Figure 1 represents an elevation of a metercontaining my improvement. Fig. 2 is a plan of the same on the lines y yof Fig. 1, showing the piston in section on the lines z 2. Fig. 3represents another form of piston and ring, in which are a larger numberof' contact bearing-points upon which the piston rocks. Fig. 4represents a similar form having curved surfaces on the piston and ring.Fig. 5 isadiagram-illnstrating the parallelogram of forces as applied inthe operation of the meter. Fig. 6 is a detail of the piston and ring,showing the application of' the parallelogram of' forces as acting 7:1upon the piston in the form contained in my invention. Fig. 7 is adetailof a piston and ring, showing a diagram of forces as acting upon apiston of a form used in the prior state of the art.

A, Figs. 1 and 2, forms the inclosing-cas'e for the piston, the samebeing provided with alternate projections and recesses, 'and having aninlet-passage, G, for conducting the waterto the center of' the case.

B is the cover which `incluses the parts, and which forms a chamber forthe water which has passed through the measuring-spaces, and from whichit is conducted by the outletpassage H. The case A is formed in such amanner that there are six projections, h' h'l h3 h" h5 h, having betweenthem six recesses. The bottom of the case is provided with conductingpassages or ports extending from openings in each recess to acorresponding open! ing in the center of the case surrounding theinlet-passage, said ports being divided by walls or divisions Thisarrangement of ports or passages is such that they are governed in theinlet and outlet of' the water bythe valve, which also forms theoperating-piston. The piston D is made of hard rubber, having fiveprojections, c c2c c4 c5, and five corresponding recesses, which are ofsuch a form that a plane passing through from the Ico The inlet-passageG and cavity.E conduct the end of one projection to the side of the oneopposite will divide the cylinder-case at n n.

water to three of the port-openings in the center of the case, fff3.These ports conduct the water to corresponding openings, e e ethat onthe right of n n being open to the inlet and that on the left of n nbeing open to the outlet. By referring to Figs. 1 and 2 theoutlet-passages and their method of operat-ion will be understood. Inthe piston is an annu lar space, o, which has communication throughholes drilled in it to the open space F in the center ofthe upper sideof the piston represented by the dotted lines. When the ports ff5f areopen to the annular space, the water is conducted from theoutlet-division of the case through the openings e e5 e to openingsf4 ffthrough the holes in the annular space to the cavity F and chamberformed by the cover to the outlet-passage H. This system of porting isduplicated in a plate on the top of the piston, which incloses thepiston in the cylinder-chamber, so that a balanced action of the pistonis obtained. By referring again to Fig. 2, it will be seen that in theposition of the piston as shown, and withthe action of the pressures asshown, when water is drawn from the outlet-chamber, the excess pressureupon one side of the piston acts to rock the piston successively uponthe points or projections a.

It will be observed thatthe form or edge of thel piston at n does notconfine the piston, but that it is free to slide or push out of placeshould anything get between the opposite abutment, and that it entirelydepends upon the action of the water to cause it to work over the pointn and upon the pressureof the water to maintain the division of t-hecase.

It will be seen that the piston is entirely free for a 'considerablespace, it being limited only by the depth of the recess in the piston.This can be governed in any construction to the size of the port; or, inother words, it can be formed so as to allow all the sliding motion orfreedom that is necessary to pass any substance that the ports willadmit into the meter.

I do not limit myself to the precise form here shown, as the form willdepend to some extent upon the number of projections upon the piston andto the shape and manner of forming the cylinder-chamber.

To accomplish the object of my invention,

` it 'is necessary to form the projections relatively upon the pistonand cylinder-chamber in such a inanner that the point of contact uponwhich the piston rocks shall be behind the direction of rotation, and insuch a manner that there shall be no shoulder upon the piston to confinethe rockingpoint, but that the rocking-point will at all times bemaintained by the direct action of the water.

It will be readily seen that this invention consists in the relativeformation of the piston and cylinder-chamber in such a manner that thepiston is in no way confined in its division of the case into separatechambers by a strictly mechanical path, but that the proper division ofthe case into supply and exhaust chambers depends entirely upon thehydraulic action, it being governed by the system of ports soarranged asto properly dispose the water in the measuring parts. By means of thisinvention the defects heretofore contained in this class of meters arewholly done away withthat is, the liability of its being stopped orlocked by any foreign substance getting into the working parts ofthemeter; and, further, that it is self-compensating in its wearthat is,all contact-points of the piston and cylinder-chamber wear alike, andthe piston is free tovfollow up this wear and still maintain `its formto properly operate, while in other forms, where the piston is confinedin' its path of movement,the lines of division will be shortened bywearing the ends of the piston projections, and allow the water to leakor pass unregistered.

To still further illustrate the scope of my invention, I will describecertain peculiarities in relation .to the bearing-points over which thepiston rocks.

An inspection of Figs. 3 and 4. and Diagrams 5 and 6 will show angularrockingpoints, by which there is a wedging effect sufficient to producecontact in the operation of the piston between the rocking-point B, Fig.5, and abut ment A. This same angular or wedging effeet will be found inFig. 2; butin these forms of meters there is but one contact-point madeby the piston in rotating from one recess into another. l In these formsit is evident thatm somewhat harsh action takes place in the operationofthe meter, owing to the few points of contact made during a rotationof the piston.

A preferable form of construction is therefore shown in Figs. 3 and 4.Referring to Fig. 3, itwll be. seen that in each recess iu the cylindercase are two angles, as indicated in one of the recesses at k and k.There are also upon corresponding sides of the piston projections twoangles. The angles upon the side of the recesses are formed atforty-five degrees to the diametric division made by the piston when ithas made its contact-bearing.

It will be seen that when the contact-point m has its bearing on theangular surface k the piston can rock ou that point until the secondcontactpoint,m,has a bearing upon the angular surface k', which is atforty-live degrees to the diametric division made by its contact. Thepiston then rocks on this point until the next contactlpoint,m,has itsbearing upon the angular surface k. This operation continues, formingcontinuously-changing contact-bearings for the piston to rock upon, eachcontactpoint causing the piston to diametrically divide the case in twochambers.

It will be seen that the relative form of the piston and cylinder-caseis such that the contact bearing-points are not mechanically defined,but that they are unconned for a considerable space, so that the 1actual contact- IOO essere n bearing will be at a point upon the angularsurface governed by the hydraulic action and upon theabutment-that is,should anything get between the piston and its abutment on the opposite.side the contact-bearing will be made lower on the angular surface, orshould the projections on the piston become worn the contact-points willbe higher up on the angle; in other words, the piston is free for aconsiderable space. This space can be governed by the relative formationof the piston and cylinder-case, and can be suieient to allow thepassage of any foreign substance that the meter is liable to admit toits working parts.

Other angles than forty-tive degrees may be' used in the formation ofthe parts,and should he that most suitable to the operation of themeter,and lit will be further considered in the following illustrations.It will be'seen that in the construction a larger number of contactbearing-points are presented, and therefore a very easy and smoothoperation of the meter is obtained.

Fig. 4 represents a similar construction to Fig. 3, with the exceptionthat curved su rfaces are formed upon the piston and cylindercaseinstead of angular surfaces.

To clcarl y demonstrate-the precise operation of the meter andthedifference of its operation over the forms at present known to the stateof the alt, I have constructed in Fig. 5 a diagram of the parallelogramsof force as applied to vthis form of meter. By referring to Fig. 5, A Brepresent a line of diamctric division of the cylinder-case or 'theoperatingpiston upon which the hydraulic force P acts. O' is any pointupon the piston at which the force is directed, as indicated by thearrow. If now an angular surface (for instance, that represented in thedotted lines indicated by twenty-tive degrees) is presented to the pointB', and upon which the piston is to rock, swinging by the abutment atA', and it is desired to know the relative contact and rotative effectsin its operation,pressnre P (represented by rotative effect. c 0'), mayby the parallelogram 0f force be resolved into c' b', or pressure atright angles to A and c B', or pressure at right angles to B',(twentyvedegrees.) It will thus be seen that the relative rotative and contacteffect-s are as c o' to c b' and c o to c' B'. As the angular surfacesat B are changed, the parallelograms offorce becomerelativelydifferent-that represented by the angle fortytive degreesproducing-,a rotative effect, e o', and contact effect e' d'. As theangle approaches ninety degrees to the direction of force, a greaterdifference of relative effects appears. For instance, at theangleeighty-five degrees there is an excess rotative et1`ect,k' o', over thecontact effect k j'. When the angleof ninety degrees is reached, thelines of parallelogram disappear,and there is rotative effect wholly andno contact-pressure.

Further reference to the operation of the piston will be understood byreferring to Fig. 6, which represents a portion-of my improved piston.

It will be seen that the angles upon the cylinder-ease are formed hereat forty-five de- 7o grecs, the corresponding angles upon the pist tonprojections' being such as to presentacontact-point which finds itsbearing upon the angular snrface,where the bearing is made and duringits rocking and until another point of 75 contact is made. This formsthe diametric division of the case at A' B'.

It will be seen that in constructing the par-` allelogram of force thereis an equal division of the pressure effects, pressure P hererepresented by rotative effect e' 0' and contact effect e' d', thecontact-pressure effects being divided into e B' contact-pressure tomaintain'the piston against 4the angle, and e' d to maintain the pistonagainst the abutment. By this constructionit will be readilyunderstoodthat thepiston can be less in diameter than that actually necessary todiametrically divide the case, thereby making it possible to move thepiston away from its abutment, and it will return by the action of thewater-pressures when the resistance to its contact is removed;

and it -will be observed by referring to Fig. 7, in which the surfacepresented is at ninety degrees to the direction of force, there is and 9must be a perfect mechanical fit to divide the case diametrically, andthat the pressure is wholly rotative. It is impossible for the piston toVassume any position in the cylindercase other t-han that which it isconfined to by mechanical fit. In my invention there exists afreecompensating piston, as clearly shown by the several illustrations,while that shown in Fig. 7 has inherent inits principle a.mechanically-confined piston and an uncompensating construction.

It will be seen from the foregoing that it is quite essential to theadvantageous working of rnyimproved form of free hydraulicallymaintainedpiston that each projection, both on the piston and casing or chamber,shall have its bearing-surface upon the end and one side only, for ifthere is a bearing upon both sides of the projection, after the mannerofthe tooth of a gear and like the ordinary practice heretofore, therewill be a locking and mechanical rigidity which it is the very object ofthis improvement to do awaywith.A Divisioncontact thus takes placebetween opposing end projections on the o-ne side and opposing sidesurfaces on the other side in distinction to the end contacts on bothsides hitherto used or shown. For the best working of the device thereare frequently two or more end projections in contact on the same sideand two or more side surfacesin contact on theopposite side, as shown.This insures a greater uniformity and ease of action. The angular sidebearing-surface may be on either the piston or casing, or on both, butalways in such 13o IOO l IIO IIS

.a manner that the piston may be free andl have the hydraulicdivision-eontact, as fully set forth.

I do not limit myselfto any particular number of contact bearing-points,or'points form ing diametric divisions ofthe case by the piston, as thesame may be so constructed as to present three or more angular surfacesupon each recess in the side of the cylinder-case, having three or morecontactpoints upon each piston projection.

I do not in any way claim as my invention the construction of a meterhaving a piston adapted to have an eccentric or side rocking motionacross the cylinder-chamber to effect its division at two or more pointsinto receiving and discharging spaces.

Having-thus fully described my invention,

I claim and desire to secure by Letters Pate'nt of the United Statesl.In a. water-meter, the combination of a casing forming a piston-chamberand having projections extending :into the chamber to form measuringspaces or recesses, each of which projections hasabearingsurfaceatitsend, with a piston having a series of projections, eaicll ofwhich has a bearing-surface at its end and an angular bearingsurfaceupon one side, as and for the purposes described.

2. In a water-meter, the combination of a casing forming apiston-chamber and having projections extending into the chamber to formmeasuring spaces or recesses, each of which projections has an angularbearing-surface upon one side, with apiston having a series ofprojections, each of which has an angular bearing-surface upon one side,as and for the purposes described.

3. In a water-meter, the combination of a casing forming apiston-chamber and having projections extendinginto the chamber to formmeasuring spaces or recesses, each of which 4projections has an angularbearing-surface 5. In a fluid-meter, a piston having aseries ofprojections, each of which has an angular bearing-surface upon one side,as and for the purposes described. l

6. In' a fluid-meter, in combination with suitable inlet and exhaustports, a ring contained in the 1netercasc and having projections fromits inner side, and forming, in connection with the portp1ates, thepiston-chamber, each of which projections has an end bearing-surface anda side bearing-surface, with a rotary piston contained in said chamber,having projections, each of which hasan end bearing-surface and a sidebearing-surface, and which piston and ring co-operate upon the rotationof the piston to divide the piston-chamber into receiving anddischarging spaces by the contact at one point of the endbearingsurfaces of a piston and ring projection, and

at another point of a sliding contact between the side bearing-surfaceof one ring projection and the side bearing-surface of a pistonprojection, substantially as described.

JAMES A. TILDEN. In presence of- F. F. RAYMOND, 2d, J. M. DoLAN.

